1. Field of the Invention
The present invention relates to a motor control apparatus for controlling a motor in accordance with rotational position data of the rotor of the motor.
2. Description of Related Art
Japanese Patent Application Laid-open No. 2005-253226, for example, discloses such a motor control apparatus for a vehicle use a brushless motor. This control apparatus outputs drive signals in accordance with detection results by a rotational position detecting function of the brushless motor when the rotational position detecting function operates normally. On the other hand, when the rotational position detecting function does not operate normally, the control apparatus outputs drive signals of a predetermined switch-over pattern, so that the brushless motor can be driven even after a fault occurs in the rotational position detecting function of the brushless motor.
The drive signals applied to the brushless motor have to be switched over at appropriate timings in accordance with detection results of the rotational position of the brushless motor. However, in the above conventional control apparatus, since the brushless motor is applied with the drive signals of the predetermined switch-over pattern when the rotational position detecting function is in a fault state, there may occur a case in which drive signals applied to the brushless motor change over at inappropriate timings, causing the brushless motor to be driven out of order.